The basic function of job offset or "jogging" to separate print jobs in printers, copiers, and separate attached output options for such devices generally has been known for some time. However, many of the prior approaches to achieving this function are expensive in that they are integrated into large, multi-function devices, and they comprise complex mechanisms. For example, many such prior devices require movable output trays, paper stack elevators, and/or shifting paper paths to offset print jobs. Other approaches utilize techniques to adjust pages "in-flight" as they fall into an output bin, or to adjust an output stack as the pages are deposited onto it.
There are a number of drawbacks associated with prior job offsetting systems such as those mentioned above. For example, most prior offset systems are limited in that the pages being output can be deposited into only two positions in the area in which the offsetting is executed. In "tray offset" schemes, the receptacle tray is physically translated or moved in a direction perpendicular to the paper travel direction. Since the tray is exposed to customers who must have access to the bin, such motion presents a distraction, and may even be a hazard. Also, for large capacity bins, large forces can be required to achieve the necessary movement. In job offset systems utilizing translating shaft-roller pairs, typically the final shaft-roller pair nearest the paper exit in the paper path is translated along the plane of the media being processed in a direction perpendicular to the media travel direction. Implementing such a scheme is quite complex, for the offset control system must adapt to or control a number of factors. For example, to avoid damage to the media, the media to be translated must clear all other drive roller pairs before the exit shaft pair, with the media still between the exit drive rollers, is translated; the translation must be complete before the trailing edge of the media leaves the exit roller pair; the exit shaft pair must reset to its original position before the leading edge of the next page reaches the exit rollers; and a separate translation-reset motion must be completed for every page that is to be offset. Further, in translating carriage systems both the back-up rollers and the drive rollers must be translated, requiring that special consideration be given to the design of the drive shaft and rollers, particularly in connecting rotational drive motion to the drive rollers. Finally, "tamping" offset systems require some type of flipper or other such device to "flick" the media to one side of a receptacle tray. Control of the media and achieving consistent placement can be problematic with such systems, since the jogging occurs when the media is "in flight" and has cleared all of the back-up and drive rollers. Thus, there are a number of significant drawbacks associated with prior job offset systems.